Mandrel stripping mechanism



May 14, 1968 Filed July 1966 F. L. HOFF MANDREL STRIPPING MECHANISM 6Sheets-Sheet 1 INVENTOR FRANCIS L. HOFF ATTORNEY May 14, 1968 F. L. HOFF3,382,774

MANDREL STRIPPING MECHANISM Filed July &, 1966 6 Sheets-Sheet 2 INVENTORFRANCIS L. HOFF ATTORNEY May 14, 1968 F. L. HOFF 3,382,774

MANDREL STRIPPING MECHANISM Filed July 5, 1966 6 Sheets-Sheet S INVENTORFRANCIS L. HOFF ATTORNEY May 14, 1968 F 1.. HOFF 3,382,774

MANDREL STRIPPING MECHANISM Filed July 5. 1966 6 Sheets-Sheet 4 INVENTORFRANCIS L. HOFF AT ORNEY May 14, 1968 F. L. HOFF 3,382,774

MANDREL STRIPPING MECHANISM Filed July 3, 1966 6 Sheets-Sheet 5 INVENTORFRANCIS L HOFF WWW ATTORNEY May 14, 1968 F. HOF'F 3,382,774

MANDREL STRIPPING MECHANISM Filed July 8, 1966 6 Shee+.sSheet 6 INVENTORFRANCIS L. HOFF ATTORNEY nited States The present invention pertains tocarton forming and filling machines and more particularly relates to amechanism for stripping cartons from a mandrel and for gripping the openends thereof.

In carton forming and filling machines of the type disclosed in thecopending US. Vadas et al. application Ser. No. 461,738, whichapplication was filed on lune 7, 1965, and is assigned to the assigneeof the present invention, a mechanism is provided for stripping thecartons from the mandrels. In the Vadas et al. mechanism a plurality ofevenly spaced mandrels are mounted on a turret and extend radiallyoutward therefrom. The mandrels have cartons thereon with their topclosures open and with their bottom closures sealed and disposed at theouter ends of the mandrels. The mandrels with the cartons thereon areintermittently indexed into an unloading station where a reciprocablestripping mechanism moves stripping fingers radially from a retracted toan extended position into engagement with the top closure of the cartonand then reverses its direction and pulls or strips the cartons off themandrels when returning to the retracted position.

If the turret and stripping mechanism become improperly synchronized sothat the turret begins swinging a mandrel out of the unloading stationbefore the stripping fingers have moved the carton off the mandrel,mechanical interference will occur between the fingers and the mandrelwhich usually results in breakage of the fingers. The mandrel strippingmechanism of the present invention is arranged to prevent such breakagein the event the turret and stripping mechanism are improperlysynchronized.

Another problem present in the prior art structure and solved by themandrel stripping mechanism of the present invention is that inherentresilience in the carton tends to cause the open end of the carton toassume a diamondshaped configuration after it is stripped from themandrel, rather than remaining in its desired square or rectangularconfiguration. If the open end of the carton is permitted to assume adiamon -shaped configuration, it has been determined that it becomesdifficult to reliably grip and transfer the carton into other componentsof the carton forming and filling machine by means of a transfermechanism such as that illustrated herein and disclosed and claimed inthe copending US. Stevenson et al. application Ser. No. 563,875 whichapplication was filed on even date herewith and is assigned to theassignee of the present invention.

It is therefore one object of the present invention to provide animproved mechanism for stripping a carton from a mandrel and forgripping the open end thereof.

Another object is to provide a mandrel stripping mechanism having afail-safe device therein.

Another object is to provide a mandrel stripping mechanism havingstripping fingers arranged to grip cartons so as to hold the topclosures thereof in desired configuration.

These and other objects and advantages of the present invention willbecome apparent from the following description and accompanyingdrawings, in which:

FIGURE 1 is a plan illustrating the mandrel stripping mechanism of thepresent invention and the components associated therewith, the strippingmechanism being ice shown in the fully extended carton receivingposition.

FIGURE 2 is a side elevation of the apparatus of FIG- URE 1 looking inthe direction of arrows 22 of FIG- URE 1.

FIGURE 3 is an end elevation of the apparatus of FIGU E 1 looking in thedirection of arrows 33 of FIGURE 1, the mandrel stripping mechanismbeing shown in a retracted carton delivering position.

FIGURE 4 is an enlarged vertical section taken along lines 44 of FIGURE3 illustrating the relationship between the mandrel stripping mechanismand an unloading trough.

FIGURE 5 is an enlarged vertical section taken along lines 55 of FIGURE1 illustrating carton guiding means associated with the mandrelstripping mechanism, only the carrier of the stripping mechanism beingillustrated.

FIGURE 6 is a vertical section taken substantially along lines 66 ofFIGURE 4 illustrating the manner in which the gripping fingers engageand grip a carton, said section being shown on the drawing containingFIG- URE 3.

FIGURE 7 is an elevation of one of the stripping fingers shown deflectedout of its normal operating position by an improperly timed mandrel,certain parts being broken away.

FIGURE 8 is a dia rammatic plan illustrating the relationship of theseveral turrets associated with the mandrel stripping mechanism of thepresent invention, and illustrating the drive for the strippingmechanism and the turrets.

In genera the mandrel stripping mechanism 18 (FIGS. 1 3) of the presentinvention forms a part of a carton transfer apparatus 29 which receivestwo rows of cartons C with their bottom closures sealed from an upperseries 22 and a lower series 24 of mandrels 25 which are supported byand are rigidly secured to an intermittently driven bottom formingturret .28. The reclprocable mandrel stripping mechanism 18 includes apair of stripper fingers and 320: (FIG. 4) associated with each mandrel,which fingers simultaneously grip and strip cartons from one of theupper and from one of the lower mandrels 26,

p move the cartons onto an unloading trough 32. Be-

fore the stoped cartons are released by the stripping mechanism E3, thecartons are simultaneously gripped by an upper jaw and by a lower jaw 38of one of a plurality of transfer heads 4%) of a continuously driventransfer mechanism which, in its preferred form is a turret 42. Theupper 3 3 and lower jaw 38 removes the horizontally disposed cartonsfrom gripping engagement with the fingers and from the unloading trough32, pivots each carton from a horizontal to a vertical position, andthen places the carton into spaced carriers 46 which are mounted on asingle continuously driven conveyor 48 and include pivotal gates 50which firmly clamp the lower end of each carton in its associatedcarrier. Substantially simultaneously as the cartons are being grippedby the associated carriers 4'5, the jaws 3'6 and 3-8 of the associatedtransfer head 4% are opened thereby releasing the two cartons "formovement along the single path of the conveyor l ne of a plurality ofanvils 52, each of which is associated with a forming head 53 of aforming turret 54, is then lowered into the open upper end of theassociated carton thus stabilizing .he upper end thereof while the j ofthe transfer head as return to the discharge station to grip anotherpair of cartons from the unloading trough 32.

More particularly, the cartons C, which are supported on the particularmandrels 25 of the upper series 22 and lower series 24 that are indexedat a mandrel unloading station 56, are strip ed from the two mandrels bythe mandrel stripping mec anism 18 which is driven in timed 7 3 relationwith the bottom forming turret 28. The bottom forming turret 28 is fullydescribed in the previously mentioned Vadas et al. application and,accordingly, will not be described in detail herein except to state thatthe upper series 22 and lower series 24 of mandrels 26 are spaced at apredetermined distance apart, the preferred centerto-center distancebeing 6 inches.

The mandrel stripping mechanism 18 comprises a carrier 58 which isslidably received on a pair of parallel rods 66 and 62 which are rigidlysecured to brackets 64 that are bolted to the frame 66 of the machine.The carrier 58 includes a horizontal base 68 having collars 70 and slideblocks '71 (FIG. thereon which are slidably supported on the rods 66 and62, respectively. An upstanding finger supporting plate '72 is integralwith the base 68 and includes three spaced horizontal finger supportingarms '73 which define horizontal slots 74 and 76 to permit the upperseries 22 and lower series 24, respectively, of mandrels 26 to passthercthrough in the event the forming turret 28 and mandrel strippingmechanism 18 should become improperly timed.

Each carton is engaged by an upper stripper finger 38 and of upperstripper finger assemblies 82 and 84 (FIGS. 4 and 6), by lower stripperfinger 38a of lower stripper finger assemblies 86 and 88. The assembliesare substantially the same except that the upper stripper fingers 30 areshorter than the lower stripper finger film so as to engage carton endclosure fiaps F1 and F2 respectively, which are of different lengths.Also, the upper fingers 38 are resiliently urged to pivot in acounterclockwise direction while the lover fingers are urged to pivot ina clockwise direction. Because the stripper finger assemblies 82, 84-,S6 and 88 are so similar, only the assembly 82 will be described indetail.

The stripper finger assembly 82 (FIGS. 4 and 6) comprises a shaft 90journalled in a suitably bushed hub 92 formed on the free end of theupper finger supporting arm 73 and held from axial movement relativethereto by a large diameter portion 94 near one end, and a washer 96 andnut 98 screwed on the other end. A torsion spring 100 is wound aroundlarge diameter portion 94 of the shaft 90 and has one end connectedthereto. The other end of the spring is connected to the hub 92 therebyurging the shaft 90 to pivot in a clockwise direction (FIG. 6).

The central portion 182 (FIG. 6) of the shaft 96 is of rectangularcross-section and is engaged by a stop bolt 1G4 screwed into the hub 92and locked in desired position by a locknut 1'35 thereby limiting theamount of spring urged pivotal movement permitted of the shaft. Theupper stripper finger 30 associated with stripper finger assembly 82(FIG. 4) is internally slotted at 166 to receive one end of the shaft 98and is connected to the shaft 96 by a pivot pin 108. The pivot pinconnection causes rotation of the finger 30 with the shaft 9% about thelongitudinal axis thereof, and also permits clockwise (FIG. 4) pivotalmovement of the finger 38 about the axis of the pivot pin 108 asindicated in FIGURE 7 in the event the bottom forming turret 28 isimproperly timed relative to the stripping mechanism 18 and causes amandrel to contact the finger 30 when moving into the unloading station56.

A notch 11!) is formed in the end of the shaft 96 and is engaged by theball 112 of a ball detent 114 which is screwed into the finger 36. Thus,the finger 30 is normaliy held in the operative position by the balldeten 114, but may be shifted out of this position without damage to thefinger 36, if one of the mandrels 26 of the bottom forming turret 28should swing laterally against the associated finger 38 or 30a. Undersuch circumstances, it is apparent that the upper finger 30 will pivotin a counterclockwise direction (FIG. 4) about their pivot pins 168while the lower fingers 36a will pivot in a clockwise direction.

As best shown in FIGURE 6, the free ends of each cooperating upper andlower pair of fingers 38 and 361! are provided with outwardly divergingnotches 116 and 118, respectively, which notches receive and firmly gripthe top closure flaps F1 and F2 during the mandrel stripping operationand retain their grip until after the cartons have been received andgripped by the jaws 36 and 38 of the transfer turret 42. It will beunderstood that the notches 116 and 118 grip the cartons with sufficientforce to not only reliably hold the cartons in position to be receivedby the associated jaws, but also maintain the flaps which define theopen ends of each carton in a square condition rather than permittingthe open end to be forced into a diamond shape by inherent resilience inthe walls of the carton.

The carrier 58 (FIG. 1) is reciprocated by a lever 124 which is securedto a shaft 126 that is pivoted in timed relation with the movement ofthe bottom forming turret 28 by means to be fully described hereinafter.In this regard, one end of a link 128 is pivotally connected to thecarrier 58 and has its other end pivotally connected by a bolt or pin130 to one of four openings 132, 134, 136 and 138 formed in the lever124 depending upon whether quart, pint, one-third quart or one-half pintsize cartons, respectively, are being handled. It will be understoodthat a carton stop 140 on each mandrel 26 will also be adjusted toaccommodate the particular size of carton being handled as fullydisclosed in the Vadas et al. application.

Pivotal movement of the shaft 126 in a clockwise direction (FIG. 2)causes the carrier 58 to move from the carton unloading position to theillustrated carton receiving position during which time the upperfingers 30 pivot in a counterclockwise direction (FIG. 6) and ride overthe upper surface of the carton on the associated mandrel 26, and thelower fingers 30a pivot in a clockwise direction and ride across thelower surface of the carton 0n the associated mandrel 26. When thefingers 30 and 30a reach the carton receiving end of their stroke, theysnap into carton receiving position under the influence of the torsionsprings 100. The free ends of the fingers are, at this time, received inlongitudinally extending slots 142 formed in the upper and lowersurfaces of the mandrels 26, which slots extend the full length of themandrels. Pivotal movement of the shaft 126 in the opposite, orcounterclockwise direction (FIG. 1) then causes the fingers to move tothe left (FIG. 1), thereby first seating carton flaps F1 and F2 in firmgripping engagement in the finger slots 116 and 118, respectively, asillustrated in FIGURE 6 and thereafter stripping the cartons off theupper and lower mandrels at the unloading station 56 for acceptance bythe unloading trough 32 in position to be engaged and gripped by thejaws 36 and 38 of the transfer turret 42.

A drive mechanism (FIG. 8) is provided for drivmg the mandrel strippingmechanism 18 and the bottom forming turret 28 in timed relation. Thedrive mechanism 158 comprises a variable speed motor M which isconnected by a belt drive 153 to an overload clutch 154 such as aMaxitorq clutch, Model No. 24, marketed by Carlyle Johnson Company, 52Main St., Manchester, Conn. The clutch 154 drives a gear reducer 156having an output shaft 158 connected by a flexible coupling 166 totheinput shaft 162 of a gear box 164 of an intermittent driving unit 166,which driving unit includes a vertically extending intermittently drivenshaft 168 to which the bottom forming turret 28 is connected. A firstcontinuously driven output shaft 170 of the gear box 164 is connected bya coupling 172 to a lower gear box 174 which is, in turn, coupled to anupper gear box 176 having a vertically extending output shaft 178. Acrank disc 180 is keyed to the output shaft 178 and has a crank pin 182adjacent its periphery which pin is pivotally attached to one end of alink 184. The other end of the link 184 is pivotally connected to alever 186 which is secured to a vertical shaft 188 pivoted in the frame66. Another lever 199 is secured to the shaft 188 and has its free endpivotally connected to one end of a link 192. The other end of the link192 is connected to a lever 194 which is secured to the shaft 126. Thus,the previously mentioned lever 124 is oscillated causing the stripperfinger carrier 58 (FIG. 1) of the mandrel stripping mechanism 18 toreciprocate thereby stripping cartons from the mandrels 26 in timedrelation with the intermittent movement of the bottom forming turret 28and placing the cartons in the pick-up station for acceptance by thetransfer turret 42.

From the foregoing description it will be apparent that the mandrelstripping mechanism of the present invention includes a fail-safe devicewhich prevents damage to the mechanism in the event the mandrelstripping mechanism and forming turret become improperly synchronized.The mandrel stripping mechanism also includes means for gripping theopen top closure flaps of a carton to maintain the top closure flaps ina squared condition and to retain gripping control of the carton untilthe carton is gripped by a transfer mechanism and pulled free from thestripping mechanism.

While one embodiment of the invention has been shown and described, itwill be understood that changes and modifications may be made thereinwithout departing from the spirit of the invention or the scope of theappended claims.

The present invention and the manner in which the same is to be usedhaving thus been described, what is claimed as new and desired to beprotected by Letters Patent is:

1. In a carton forming machine a mandrel stripping mechanism forstripping cartons of generally rectangular cross section with one endclosed and the other end open from a mandrel comprising, the combinationof an intermittently driven turret, a mandrel on said turret movablealong a first predetermined path and intermittently indexed into anunloading station, stripping means movable between a retracted positionout of the path of movement of said mandrel and an extended position inthe path of movement of said mandrel, drive means for synchronizing themovement of said turret and said stripping means for effecting movementof said stripping means along a second path from the retracted positionto the extended position and back to the retracted position While saidmandrel is indexed at said unloading station, and failsafe meansincluded in said stripping means for allowing movement of said strippingmeans laterally of said second path out of the path of movement of saidmandrels in the event said mandrel moves out of the unloading stationbefore said stripping means reaches said retracted position and contactssaid stripping means.

2. An apparatus according to claim 1 wherein gripping 4. An apparatusaccording to claim 3 wherein inherent resilience of the carton tends totwist the open end of the carton when removed from the mandrel from adesired rectangular condition to a diamond-shaped condition, and whereinmeans defining slots are provided in each finger for receiving edges ofopposed walls of the open end of the carton to grip the carton tomaintain the open end in rectangular configuration.

5. An apparatus according to claim 1 wherein said stripping meansincludes a carrier movable along said second path, a pair of shaftsjournalled in said carrier with the shafts disposed on opposite sides ofsaid first path and projecting outwardly from said carrier in adirection normal to said second path, a stripping finger pivotallyconnected to the end of each shaft and each finger having an end portionprojecting into said first path, and said fail-safe means includingresilient releasable means for normally holding said fingers frompivotal movement rela tive to said associated shafts.

6. An apparatus according to claim 5 wherein torsion springs aredisposed between said carrier and said shafts for urging said fingers inopposite directions into the path of movement of said mandrel, andwherein adjustable stop means are provided between said shafts and saidcarrier for limiting the extent of pivotal movement of said fingerstoward said mandrel, said fingers being deflected over the adjacentwalls of the cartons against the urging of said torsion spring as saidstripping means moves from the retracted to the extended position.

7. An apparatus according to claim 5 wherein means defining slots areprovided in each finger for receiving opposed walls of the open end ofthe carton to grip the carton to maintain the open end in rectangularconfiguration.

8. An apparatus according to claim 6 wherein means defining slots areprovided in each finger for receiving opposed walls of the open end ofthe carton to grip the carton to maintain the open end in rectangularconfiguration.

9. An apparatus according to claim 6 wherein the end of each shaftadjacent said stripping fingers are semicylindrical, and wherein each ofsaid resilient releasable means is a ball detent which cooperates with agroove in the semi-cylindrical end of the associated shaft.

10. An apparatus according to claim 7 wherein the end of each of saidshafts adjacent said stripping fingers are semi-cylindrical, and whereineach of said resilient releasable means is a ball detent whichcooperates with a groove in the semi-cylindrical end of the associatedshaft.

References Cited UNITED STATES PATENTS BERNARD STICKNEY, PrimaryExaminer.

1. IN A CARTON FORMING MACHINE A MANDREL STRIPPING MECHANISM FORSTRIPPING CARTONS OF GENERALLY RECTANGULAR CROSS SECTION WITH ONE ENDCLOSED AND THE OTHER END OPEN FROM A MANDREL COMPRISING, THE COMBINATIONOF AN INTERMITTENTLY DRIVEN TURRET, A MANDREL ON SAID TURRET MOVABLEALONG A FIRST PREDETERMINED PATH AND INTERMITTENTLY INDEXED INTO ANUNLOADING STATION, STRIPPING MEANS MOVABLE BETWEEN A RETRACTED POSITIONOUT OF THE PATH OF MOVEMENT OF SAID MANDREL AND AN EXTENDED POSITION INTHE PATH OF MOVEMENT OF SAID MANDREL, DRIVE MEANS FOR SYNCHRONIZING THEMOVEMENT OF SAID TURRET AND SAID STRIPPINGS MEANS FOR EFFECTING MOVEMENTOF SAID STRIPPING MEANS ALONG A SECOND PATH FROM THE RETRACTED POSITIONTO THE EXTENDED POSITION AND BACK TO THE RETRACTED POSITION WHILE SAIDMANDREL IS INDEXED AT SAID UNLOADING STATION, AND FAILSAFE MEANSINCLUDED IN SAID STRIPPING MEANS FOR ALLOWING MOVEMENT OF SAID STRIPPINGMEANS LATERALLY OF SAID SECOND PATH OUT OF THE PATH OF MOVEMENT OF SAIDMANDRELS IN THE EVENT SAID MANDREL MOVES OUT OF THE UNLOADING STATIONBEFORE SAID STRIPPING MEANS REACHES SAID RETRACTED POSITION AND CONTACTSSAID STRIPPING MEANS.